This invention relates to cluster weapons and to a means for effecting their dispersion. In a more particular aspect, this invention concerns itself with the forced dispersion of tightly clustered submunitions by a propellant/foam material.
With the recent interest in the tactical employment of cluster weapons and from an analysis of the operational requirements for future weapon systems, it has been found that a need exists to enhance the delivery flexibility of both guided and unguided cluster weapons and to maximize the benefits of terminally guided cluster weapons. This operational need dictates a requirement to develop a quick-acting submunition dispersion mechanism. A quick-acting dispersion mechanism is defined as one that does not affect weapon flight prior to warhead event and achieves required dispersion velocities within a fraction of a second after the event. In addition to the quick-acting feature, a dispersion mechanism capable of providing higher dispersion velocities than are attainable with current techniques is also needed. Higher dispersion velocities are defined as approximately twice those attainable with current augmented dispersion mechanisms, such as warhead spin, slings, and bladders.
In an attempt to satisfy the need for an effective submunition dispersion system, it was found that a polyurethane explosive propellant foam provided a feasible, quick-acting, high-velocity dispersion mechanism for dispersing clustered munitions.
Propellant dispersion is simple in concept. It consists of igniting energy rich gas generating grains of propellant locked in a low density plastic foam matrix. The propellant foam can be formed in panels and placed between cargo layers, or formed into a central core extending longitudinally in the dispenser to obtain rapid dispersion of the dispenser cargo, or cast into place in the interstices of an unconfined cluster of submunitions or projectiles located within a bomb casing.
At a predetermined time or position along the dispenser trajectory, the propellant is ignited. Resultant gas pressure ruptures the container or bomb casing and rapidly disperses the submunition cargo. The ignition, rupture, and cargo acceleration processes are completed within approximately two milliseconds. Controlling the amount of propellant ignited or the density of the foam material provides control of ground pattern size and uniformity.
Quick action and higher velocity dispersion are the major benefits of the propellant dispersion technique of this invention. These features overcome the negative characteristics of prior art dispersion techniques and provide the needed improvements in delivery flexibility and accuracy. In addition, propellant dispersion offers the following benefits, all of major concern in cluster weapons.
It is simple with a low end-item cost. There is a low weight to volume ratio resulting in an insignificant loss in cargo. From a safety standpoint, there is no degradation in weapon system safety. It has many applications and is compatible with a wide spectrum of weapons. It has particular utility for wide area munition dispersion from low altitude-high speed aircraft. It provides a very good arming environment since high pressure pulse can be used for rapid submunition arming. Also, the dispersement pattern for the submunitions can be easily controlled, thereby preventing voids in the pattern and optional detonating schemes can be employed to initiate a high or low dispersion velocity.